The present disclosure is related to medical procedures for the treatment of pain, spinal disease, neurologic dysfunction and neoplasms.
Chronic pain is one of the most common and disabling disorders afflicting humanity. In the United States alone, more than 50 million individuals live with the burden of chronic pain and, for at least two thirds of these Americans, the pain has been present for more than five years. The economic costs of chronic pain to both the sufferer and society are substantial. Recent studies show that more than 35 million Americans will miss work each year because of pain and at least 80 million Americans with chronic pain live with significant limitations in functional capability and quality of life.
Spinal cord injury and other insults to the nervous system—such as stroke, traumatic brain injury, traumatic disruption of the peripheral nerves, and the like—are additional causes of devastating disability. In addition to producing chronic pain, these afflictions can permanently disable otherwise productive members of society. While the initial injury disrupts the functional status of the nervous system, it is the formation of scar tissue at the site of injury that greatly retards neuronal healing and turns the initial functional deficit into a permanent neurological disability.
The limited capacity of human organ systems to repair and restore function after injury is well known. Unlike some species that are capable of complete organ or limb regeneration, human organ systems respond to injury by forming scar tissue. With the exception of bone, all human organ systems will produce varying amounts of scar tissue in the healing process. Since scar formation replaces the native functional tissue with non-functional scar, the healing process necessarily produces a repaired organ system with diminished capability.
In general, the regenerative capability of an organ system is inversely proportional to its level of specialization and complexity. As the most specialized organ system, the nervous system has a limited capacity to regenerate and recoup function after injury. This is especially evident in spinal cord injury. Patients who suffer significant spinal cord trauma may not regain any meaningful function. Recent studies into the cellular events that occur after nervous system injury have demonstrated that scar formation is a major limiting factor in recovery. That is, the forming scar limits the extent of neuronal regeneration and inhibits the re-establishment of normal communication between nerve cells. Likewise, the inhibition of scar formation has been shown to increase functional recovery after injury.
Radiation is a known inhibitor of the healing process and scar formation. Because of the negative effect on healing, the exposure of injured tissues to radiation is generally undesirable and contra-indicated. Irradiation of injured neural tissue can paradoxically improve neurological recovery by limiting the extent of scar formation. However, a radiation source external to the body is indiscriminate and cannot be effectively used to selectively radiate an injury site while sparing the surrounding tissues.
This is an inherent limitation of the use of external beam radiation sources that cannot be readily circumvented. In view of the foregoing, there is a need for improved systems and methods for treating injury, including neurological injury.